Hydraulic valve.



E. s. MATTHEWS.

HYDRAULIC VA'LVE. APPLICATION FILED MAY23, |913.

Patented May 23,1916.

3 SHEETS-SHEET l.

WIN/8858 VVE. S. MATTHEWS.

HYDRAULIC vALvE.

THB COLUMBIA PLANOGRAPH C0.. WASHINGTON, D. C;

E.' s. MATTHEWS.

HYDRAULIC VALVE.

APPLICATION FILED MAY 23| 1913..

Patent-ed May 23, 1916.

3 SHEETS-SHEET 3.

INVENTOH sa aren rica; l'

EDWIN S. MATTHEWS, 0F NEW YORK, N. Y., ASSIGNOR TO JOHN S'. HOY T AND WILLIAM H. WOODIN, BOTH OF NEW YORK, N. Y.

HYDRAULIC VALVE.

Substitute for application Serial No. 289,732, led. December 1, 1905.

Specification of Letters Patent.

Serial No. 769,436.

To all whom t may concern Be it known that I, EDWIN S. MATTHEWS, a citizen of the UnitedI States of America, and a resident .of the borough of Manhattan, city, county, and State of New York, have invented certain new and useful Imw provements in Hydraulic Valves, of which the following is a full, clear, and exact description, reference being had` to the accompanying drawings, which form a part of the specification.

My present invention relates to hydraulic valves, or valves which control thellow of fluid with precision, and particularly to such valves as are adapted to control the operation of fluid motors.

The objects of this invention are, broadly,

to insure certainty, precision, 'and refine-- ment in such control, and consequently increased efficiency in the practical service of such motors.

F or illustration, as applied to a hydraulic plunger elevator, my present invention gives a control of the rate of fluid flow so that starts and stops in either direction are automatically regulated to provide maximum acceleration of the necessarily heavy mass to be moved, accompanied by suitable retardation; also secures an improved reversal eliminating the waste of time consumed in idle lap travel in the controlling valves'now in use; also avoids possible creeping atl landings caused by leaky pilot valves or actuating pistons by the use of a locked stop position; and further gives the operator control of the rate of speed Vof the caraccording to the degree of opening he gives the pilot valve, while further objects of the invention will hereinafter appear as Vit is described in detail.

The structure herein shown and described as embodying my invention is a doublebodiedhydraulic valve, which I have termed a duple'x controlling valve, and belongs to that class of valves wherein the controlling pistons which govern the fluid flow are themselves moved or held in position by the fluid pressure of the system to which it is applied, their position and their motion, both in direction and extent, being governed by a pilot valve which is moved by the operator by any approved means; while the speed of their motion is governed by the fixed adjustment of water passages communicating with the pilot valve. A

the pilot valve with the pistons of both of which may. be designated as a double ioating fulcrum system (in distinction from the Afloating' fulcrum control shown in Rey- 'noldss Patent #314720, Matthewss Patent #465611 and which is well known in the practical art), enables both units of the duplex valve to be operated from a common pilot valve, and this system as a mechanical movement, as well as this application of it,

is as far asl am aware, broadly new. Byk causing one unit of the duplex valve to` control the turning on and the turning off of the water supply to the motor, and the other unit to control the opening up of the discharge of the motor and its closing, I

peculiar arrangement of levers connecting- `the valve bodies and the operators control obtain a greater {iexibility of the control of y the motor than is afforded by any form of three way valve.

Another important feature of this in vention is the duplex locking control by means of which one unit while it is in lof the main valve pistons, and the balancing'and unbalancing of pressures therein, as well as the use of holding pressure against a positive shoulder stop, at the time of valve closure, is also new; and this as well as other features of the invention arising from the construction, combination,

`location and relative arrangement of parts and the resulting control of forces will be hereinafter more fully set forth in the accompanying drawings, and detailed description of the valve illustrating this invention in its preferred form, and the new and novel feature of the invention will be finally pointed out in the appended claims.

Referring now to the three sheets of accompanying drawings, it will be assumed for the sake of clearness that the left hand unit or cylinder is connected with the source of fluid supply under pressure, and that the right hand unit or cylinder is connected with the exhaust having a lowerl pressure than the source of supply, or Without pressure.

Figure 1 represents my improved valve partly in section, in closed position. Fig. 2 is a top plan view of the same. Fig. 3 is a section of the same on the line 3-3 of Fig. 1. Fig. 4 shows the position of parts when the supply valve is wide open. Fig. 5 shows the position of parts when the exhaust valve is wide open. Fig. 6 shows the position of parts for opening the supply valve. Fig. 7- shows the position of parts in reversing when the supply valve has nearlv closed and thev exhaust valve is moving over its lap in opening.

Referring now to Fig. 1 it will be seen that 1 represents the supply valve and 2 the. exhaust valve connected respectively by passages 3 and 4 with a pressure water supply and an exhaust tank or sewer. From said valve pipes 5 and 6 lead preferably to a common pipe 7 which is connected with the Inotor cylinder (not shown) in the usual man-- ner. The supply valve 1 comprises a stem 10 having the controlling piston 11, the bal- /ancing piston 12 and the actuating piston 13,

the piston 11 controlling the port 14 leading to the pipe 5. In the exhaust valve 2 the corresponding parts are numbered 15, 16, 17, 18, and 19 respectively. The pilot valve consists of the cylinder 21, having supply passages 22, 23, at opposite ends, supply and discharge ports 24, 25, and exhaust passage 26: the ports 24, 25, being controlled by pistons 27,28, mounted on the stem 29. The main and pilot valves are preferably brasslined and all pistons are preferably provided with cup leather packings placed concave toward the pressure to be controlled in the manner well known in the art. The passages 22, 23 are supplied by the pipe 30 which is itself supplied by a pipe 31 provided with a regulating cock 32 leading to a source of pressure in the space 33 between the pistons 17 and 18 of the exhaust valve cylinder; while the upper and lower portions of pipe 30 may also be provided with regulating cocks if it is desired to varv the relative 'speed' of closure of the supply and exhaust valves. The space 33 and consequently both ends of the pilot valve (through passages 35) are always under supply pressure, 34 being a supply pipe leadingrto this space. The supply pressure on pistons 27 and 28 balances the pilot valve in all positions, which is also balanced in case of any back pressure from the exhaust which is connect- ,ed'to the pilot valve through the passage 26 which leads through the pipe l39 to the space 41 in the supply valve, this space being always open to the exhaust through passages 42 and pipes 43, the aforesaid pipe 39 being also provided with a regulating cock 40. From the port 24 of the pilot valve a pipe 36 leads to an auxiliary valve chamber 37 of cylinder 1 from which chamber there is communication by passage 38 (see Fig. 3) with the space above the actuating piston 13 of the supply valve 1. This chamber will also be seen in dotted lines in Fig. 1 on the rear side of cylinder 1. From the port 25 of the pilot valve a pipe 45 leads to the auxiliary valve chamber 46 of cylinder 2 which communicates by a passage 47 with the space 48 above the actuating piston 18 of the exhaust valve 2.

It will be observed from Fig. 1 (both valves being closed and the motor at rest) that the pilot valve pistons 27 and 28 are so disposed as to normally (in this said position) allow a slight passage ofthe water around their outside ends through their respective ports 24 and 25, thus transmitting pressure to the upper sides of the actuating pistons 13 and 18 of both the supply and exhaust valve positively seating them Vdown upon the solid shoulders beneath them thus holding these valves iirmly closed against leakage of either pilot valve pistons or the actuatingV pistons when they are both in closed position and the motor is at rest. p

The two unit valves comprising the duplex controlling valve, which govern the supply and discharge ofifluid from the motor are caused to move by the pressure of the fluid supply and operate in the following manner: When the valves are in closed position as in Fig. 1, it is seen that in the case of the supply valve 1, Vthe supply pressure on controlling piston 11 Ytends to open the valve, which tendency is overcome by the supply pressure on actuating piston 13 through pipe 30, pilot valve port 24, pipe 36, chamber 37, passage 38 because of the larger area Vof piston 13. In the exhaust valve 2 the same result is secured as to locked stop or closed position because while there is supply pressure on both sides of the large piston 18 thus balancing it, the downward pressure of the supply on piston 17 is not opposed by other hydraulic pressure there being no upward pressure on piston 16 which communicates Vwiththe exhaust. Thus both valves are -held .seated in closed positionV and if the areas of pistons 13 and 18 be each twice that of pistons 11 and 17 respectively the differential closing Vpressure on either valve is equal to that on the other.

In order to open the supply Valve, referring now to Fig. 6, the pilot valve is openedVV by the operator to the position therein shown, whereupon the pistons V28 and 27 having cut off the supply pressure on actuating piston 13 andalso having opened the space aboveV that piston to the exhaust through passage 38, pipe 36,1 pilot valve ports, and passages 24 and.26 respectively, pipe 39, passages 42, and pipe 43,-the supply pressure on controlling piston 11 opens the supply valve to the position shown in Fig. 4, the latter at the same time by its motion closing the pilot valve through connections to be hereinafter described. It will be seen that this operation of the pilot valve and the consequent opening of the supply valve 1 has no effect upon the exhaust valve 2 as its pressure conditions remain unchanged during this operation.

1n order to open the exhaust valve to the position shown in Fig. 5 the pilot valve is moved in the opposite direction from that mentioned above so as to connect the port 25 of thepilot valve with the passage 26 thus opening .up the space above actuating piston 18 of the exhaust valve to the exhaust through the same discharge channel already mentioned above, thus opening the exhaust valve in a manner now obvious. This actuation or opening of the exhaust valve in its turn, does not affect the supply valve 1 whose pressure conditions remain unchanged, in turn, during this operation.

It is now obvious that in either of the above cases, after the valve is fully opened, if the operator should return his control switch or mechanism to the central point, or position, calling for stoppage of the motor, thus causing the control point on the valve lever system to once more occupy the position which it has in Fig. 1 that the supply pressure would be admitted over the controlling piston of either one of the valves 1 or 2 as the case might be, thus closing it while the pilot valve is again returned to central position as shown in Fig. '1 by mechanism to be fully described in detail hereinafter, the operation in this respect being similar to that of tlie valve of the Reynolds Patent #314,720 and the Matthews Patent :VL/:465,611 before quoted and being well known to the art. 1f the operator were to move his controlling switch or mechanism abruptly from full speed in either direction to full speed in the reverse direction, it

would permit one valve to commence to open while the other is closing, and this characteristic of this invention I govern by means of auxiliary valves 5() and 51 (see Figs. 1 and 3) so as to secure a smooth and practically instantaneous reversal; thus obviating the waste of time inherent in all three way valve constructions while such valves are traveling over the double idle lap of the main valve, which it is impracticable to shorten suiciently to obviate such delay. According to my invention, in reversing, while one valve is closing, the other is moving over its lap in opening and thus the motor can be practically instantaneously reversed, which is of great value in elevator practice on account of saving of time where landings are overrun, and must be returned to, in order to be made accurately.

If the mechanism thus far described be considered, assuming the supply valve to be wide open, and the pilot valve closed as in Fig. 4, in order to quickly reverse the motor, the pilot valve will be given a double throw upward so as to let full supply pressure above actuating piston 13 of the supply valve. This movement will also connect the pilot valve port 25 with the passage 26 which would permit the supply pressure under actuating piston 18 of the exhaust valve to open said valve before the supply valve had closed, the pilot valve not closing until both valves had reached their limit of movement, resulting in a loss of supply water by connecting for an instant the supply pressure directly across to the discharge. An exactly similar result would take place under similar circumstances in reversing from the wide open position of the exhaust valve. I therefore provide means which will prevent both valves from being open at the same time, but which will permit either valve to be moving over its lap in opening while the other valve is properly approaching its lap in closing, both valves being in motion in opposite directions during this operation at the same time. This I accomplish by means of the auxiliary valves 50 and 51 (see Figs. 1 and 3) which control the respective passages 45 and 36 and thereby, when closed at proper times lock the exhaust and supply valves respectively against any movement whatever from a closed position; and at the proper instant, when opened, unlock these valves so that they may move. Preferably I cause the supply and exhaust valves to reciprocally control each other, so that when both are closed either can be opened, and the opening of one will lock the other until the one which was opened has returned to such a position that it will be closed before the other can be opened.

The valve 50 in the chamber 46 (see Fig. 1) is mounted on a stem 52, and is normally held closed by a spring 53, while 54 is a head which is engaged by an arm 55, fastened to a shaft 56, which latter is mounted in journals 57 in the cylinder heads. A53 is another arm fastened to the opposite end of shaft 56, which arm is of such length as to be engaged by a projection 59 on the valvestem 10 and depressed as shown in Fig. 1, opening valve 50 against the pressure of spring 53. The projection 59 is so located that it will strike the arm 5S when the piston 11 of the supply valve is slightly above the position shown in Fig. 7, this figure showing both valves in motion, the supply valve being nearly on its lap in closing and the exhaust valve being nearly off its lap in opening. The corresponding parts for controlling valve 51, on stem 61, are spring 62,

lso

, closed, with the shafts 56 and 65 rocked so as to open both auxiliary valves 50 and 51.

It will therefore be seen that by adjusting the positions oi' the projections 59 and 67, the opening of the auxiliary valves can be timed as may be desired. As has been before stated the pilot valve is closed by the movements of the supply and exhaust valves, the connections of which with the pilot valve will be described hereinafter. From the position shown in Fig. 4;, to close the supply valve 1, the pilot valve is moved upward, and this movement also opens up the exhaust from above piston 18, of the exhaust valve, so that both valves would move together, but for the closing of passage 15 by the valve 50, which took place as soon as the projection 59 on the supply valve-stein 10 had moved upward when that valve was opening, suiiiciently to allow spring 53 to close valve 50. In Fig. 5 the spring 62 closed valve 51 as soon as projection 67 on valve-stem 15 had been moved upward far enough in the opening. In practice the auxiliary valves 50 and 51 are adjusted to close when the supply valve or exhaust valve respectively opens to an extent slightly less than the lap. In Fig. 7, the projection 59 of the closing supply valve has just opened auxiliary valve 50 of the opening exhaust valve, both valves being in motion, and the actuating piston 1S of the exhaust valve having moved slightly upward in the performance of quick reversal; it is seen that the discharge will be opened to the motor as soon as the supply is cut off from it, and that the auxiliary valve 51 of the supply valve will be closed as soon as a slight opening of the exhaust valve occurs. This closing of these auxiliary valves on the opening movements of the supply and exhaust valves serves the function of entirely cutting oii the inactive valve and preventing any operation whatever' of it, until the other valve has nearly returned to its closed position. pending entirely upon the relative positions of the two valves and yet permitting quick reversal, independent of the amount of lap, is so far as I am aware, broadly new.

' This duplex valve is controlled by the operator through a pilot valve which is ca.- pable of receiving motion both from the operator, and from either one of the unit valves comprised in the duplex valve, in such a manner that the choice of unit to be opened and the extent of opening of eitherunit valve, is regulated by the direction and the extent of motion given the pilot valve by the operator from its central or stop position; to which central position it is automatically returned by the corresponding movement This construction, de-` of either unit valve; thus permitting the operator, by bringing his switch or controlling mechanism to a central position, to close either valve which may have been opened, and cause the duplex valve as a whole to respond, in the control ot' a fluid motor, to the operators manipulation of its pilot valve through any approved switch or mechanism (not shown because familiar in the art) when he moves its controlling point to positions of stop, motion in one direction at desired speed, or motion in the opposite direction at desired speed. -The pilot valve is, for this purpose, operated by a system of interconnected levers which dii'ers from the well known pilot valve lever of thethree way pilot operated valve in that the central point of the interconnected levers becomes alternatively a floating fulcrurn for either one of the unit valves as may be required instead of merely for one valve, and this system is, so far as I am aware, broadly new. It is constructed and arranged as follows: Pivoted on the valve-stems 10 and 15 at 69 and 70 are levers 71 and 72 one of which as 7 2 is connected with the pilot valvestem 29 by a link 73, and the other, as 71, is connected with the operators controlling means as, for example in this instance by a shipping rope 74. This rope may pass through a swiveled eye 75 and have clamps on both sides of the eye (see Fig. 3) so that longitudinal movement of the rope will also move the lever. The levers are connected together pivotally at 76 so that movement of lever 71 will also move the pilot valve through lever 7 2; and, to avoid slotting the levers, the pivot 76 is divided and each part is connected by links 78 with a vertically moving slide carried in a guide 80; so that, while the pivots 7 6 cannot become vertically displaced relatively to each other, they are free to swing in arcs about the pivots 69, 70 which attach their Vrespective levers to the unit valve-stems. Figs. 6 and 7 show the pivots 76 laterally displaced relatively to each other according to the particular positions of the two unit valve-stems.

In order to open the supply valve 1 from the closed position of Fig. 1, the shipping rope is moved downward and the parts assume the position shown in Fig. 6, the pilot valve being now open but the parts of the unit supply valve not yet in motion. In this position of the pilot valve the unit supply valve moves upward in opening, as before described, and closes the pilot valve because lever 71 swings about the eye as a center (this point being held fixed vertically by the operators switch or other mechanism) and lifts the pins 76, swinging lever 72 about pivot 70 to the position shown in Fig. 1, the operation of the device being obvious in view of the preceding explanation. The unit exhaust valve closes the pilot valve when opening by swinging the lever 72 on the pivot 76, lever 71 remaining stationary, and its action in closing is obvious. In case the operator had but partially opened the pilot valve, it is seen that it would be closed by a partial opening of a unit valve, hence the degrees or extent of opening of the unit valves is governed by the extent to which the operator opens the pilot valve.

Now referring to the speed of opening and closing the unit valves, and consequently the control of the time of stopping and starting the motor to which the duplex valve is applied, it will be seen, for instance, that in closing the exhaust unit valve 2, the pipes 31, 30, and 45 form a circulating passage around the actuating piston 18, and by adjusting the cock 32 in this passage, the speed of closing the exhaust valve may be varied; and by adjusting` the cock l0 the speed of opening the exhaust valve is controlled. The cock 32 also controls the rate of flow of water which passes through the pilot valve and pipe 36 in closing the supply valve, and consequently its speed in closing; while the speed of opening the supply valve is governed by the cock t() because the pipes 35 and 39 then form a circulating passage around both sides of piston 13 preventing the latter from moving any faster than water can be exhausted through cock 40. ln case this valve is applied to a direct plunger elevator the rapidity of starting, whether ascending or descending, will be controlled by the cock 40, and of stopping by the cock 82; and by simply widely opening the cock ll0 quick starts are secured, and by partially closing the cock 32 retarded stops will be accomplished, or vice versa. rlhis will, in general, be an adequate regulation; but, 1f it is desired to vary the up and down control separately, cocks may be placed in the upper and lower vertical portions of the pipe 30 instead of in the pipe 31, as cocks 81, 82; or other methods of throttling may be used.

Many variations in the construction of details and the location and relative arrangement of parts would readily suggest themselves to persons skilled in the art to which this invention relates and still fall within the spirit and scope of my invention. lf do not desire therefore to be limited or reof opening of said valves is independent of that of closing, said elements being constructed and arranged to cause said valves to move under supply pressure in both directions, substantially as described.

2. The 'combination with a pair of reversible fluid motors, of a valve for controlling said motors, means independent of said controlling valve for controlling the exhaust to regulate the speeds in one direction, and means controlling the supply to regulate the speeds in the other direction, whereby the movements of said motors can be independently regulated, one by the supply and the other by the exhaust, substantially as described.

8. The combination with a pair of reversible iuid valve motors and valves actuated thereby, of a valvefor controlling said motors to open and close said valves, a fixed throttle governing the exhaust of said m0- tors, whereby said valves may be opened relatively quickly, and an independent fixed throttle governing the supply of said motors, whereby said valves may be closed relatively slowly, substantially as described.

el. The combination with a pair of reversible fluid valve motors and valves actuated thereby, of means for controlling said m0- tors, and means for automatically locking one motor to prevent opening the valve actuated by it, while the valve actuated by the other motor is open, substantially as described.

5. The combination with a pair of reversible fluid valve motors and valves actuated thereby, of means for controlling said motors, and means independent of said controlling means for auto-matically locking one motor to prevent opening the valve actuated by it, while the valve actuated by the other motor is open, said locking means being controlled by the position of the valve which is open, substantially as described.

6. The combination with a pair of reversible fluid valve motors and valves actuated thereby, of means for controlling said motors, and means whereby one of said valves can be moved over its lap to open before the other valve is closed, substantially as described.

7. The combination with a pair of reversible fluid valve motors and valves actuated thereby, of means whereby the movement of one motor automatically locks the other motor, substantially as described.

8. The combination with a pair of reversible Huid valve motors and valves actuated thereby, of means whereby a predetermined movement of one motor automatically throws the other motor out of operation, substantially as described.

9. The combination with a pair of reversible fiuid valve motors and valves actuated thereby, means whereby a predetermined movement of one` motor in opening its valve automatically locks the other motor, and means whereby said motor is automatically unlocked when the other motor has moved a predetermined distance in closing its valve, substantially as described.

l0. The combination with a pair of reversible fluid motors and valves actuated thereby, of a valve for controlling said motors, an auxiliary valve for each motor, and means whereby the movement of one motor, to open its valve, closes the auxiliary valve of the other motor to prevent its operation, substantially as described.

l1. The combination with a duplex controlling valve, having a pair of reversible fluid motors and valves actuated thereby, of apilot valve, controlling said motors, and connections between the pilot valve and said motors coordinating the movements of said motors, said elements being constructed and arranged to cause said valves to move under supply pressure in both directions, substantially as described.

l2. In a duplex controlling valve having two fluid motors operatively arranged to actuate valves by the utilization of supply pressure on differential areas, the combinationof one reversible fluid motor having a differential chamber always open to supply pressure, with another reversible fluid motor having a differential chamber' always open to exhaust pressure and means for regulating the rate of movement of said motors, substantially as' described.

13. The combination of a pilot valve operated fluid controlling valve, adapted to control a fluid motor, with a fixed throttle for the pilot valve, regulating the rate of closing of the said controlling valve independently of its opening motion.

,14. The combination of aY pairY of reversiblefluid motors, controlled by a pilot valve, and connections between thel pilot valve and said motors, coordinating the movements of the motors, said elements being constructed and arranged to cause said motors to move under supply pressure in both directions, substantially as described.

15. The combination of a pair of pilot valve operated reversible fluid motors, with a fixed throttle for the pilot valve, regulating the speed of movement of the said motors, in one of reverse directions, independconnection between the'pilot valve and said motors, coordinating themovements'of the said motors, said elements being constructed:

and arranged to cause said valves to move under supply pressure in both directions, substantially as described.

18. VThe combination with Va pair of re-V fluid motors and valves actuated thereby, of i means for starting, stopping, and cordinat! ing the movement of said 'fluid motors, means for regulating the speed of said movement independently in reverse directions, and means for automatically locking one motor to preventits operation, while the other motor is in Vpredetermined position.

20. The combination with a duplex controlling valve, having a pair of reversible fluid motors, valves actuated thereby,and a pilot valve controlling said motors, Voffconnections between said motors and the pilot valve, whereby any proportional opening of the pilot valve, to operate either motor, is

closed by the resulting proportionallm ove-V ment of that particular motor, said elements being constructed and arranged to cause said valves to move under supply `pressure inA botlirdirections.V Y V- 21. The combination with a Vduplex, con@ trolling valve, `having arpair of reversible motors, valves actuated thereby, and a pilot valve for said motors, of connections interacting between tlie operators control point,l

the pilot valve, and both theV said reversible motors, controlling the movements of said motors and the pilot valve, said` elements being constructed'and arranged, to cause said valves to move under supply pressure in both directions, Vsubstantially Vas hereinbefore set forth.

22. The combination with a duplex controlling valve having a pair of differential reversible fluid motors'and valves actuated thereby, of a pilot valve operatively connected thereto, and having a-fluid passage provided with a fixed throttle, for regulating ioo iit

the speed of movement of the said fluid mo-V Y tors, said elements being constructed and arranged to cause said valvesstomoveV underV supply pressure in'both directions.

23. The combination with a duplex controlling valve, having a Vpair ofV reversible 'A fluid motors, and valves actuated thereby, Vof a pilot valve operativelyV connected thereto,

having a fluid passage provided witha fixed throttle, for regulatingfthe speed of moveiso ment of the said fluid motors, and means for automatically locking one of the said motors, While the other motor is in a predetermined position.

24. The combination With a duplex controlling valve, having a pair of reversible iuid motors, and valves actuated thereby, of means whereby the said fluid motors reciprocally and automatically lock and unlock each other at predetermined points as described.

25. In a duplex controlling valve, having two fluid motors operatively arranged to actuate valves by the utilization of supply pressure on differential areas, the combination of one reversible luid motor having a diferential chamber always open to supply pressure, with another reversible fluid motor, having a differential chamber always open to exhaust pressure, substantially as described.

26. In a duplex controlling valve, the combination with a pair of fluid motors and valves of a single pilot valve operatively connected to both motors, said elements be-V ing constructed and arranged to cause said Copies of this patent may be obtained for five cents each, by addressing the valves to move under supply pressure in both directions, substantially as and for the purpose set forth.

27. A duplex controlling valve, having tWo fluid motors operatively arranged to actuate the valves by the utilization of supply pressure on differential areas.

2S. A pair of reversible fluid motors operatively arranged to be actuated by the utilization of supply pressure on differential areas.

29. A duplex controlling valve having two members adapted to control a filiid inotor, having two fluid motors for said members, constructed and arranged to actuate the said members by the utilization of pressure on differential areas, independent of the pressure in the controlled motor.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

EDWIN s. MATTHEWS.

Vitnesses:

A. R. MATTHEWS, T. C. MEUNIER.

Commissioner of Patents,

Washington, D. C. 

